0wning Vista from the boot

The VBootkit authors speak out

InterviewFederico Biancuzzi interviews Nitin and Vipin Kumar, authors of VBootkit, a rootkit that is able to load from Windows Vista boot-sectors. They discuss the "features" of their code, the support of the various versions of Vista, the possibility to place it inside the BIOS (it needs around 1,500 bytes), and the chance to use it to bypass Vista's product activation or avoid DRM.

Could you introduce yourselves?

Nitin Kumar: I am a 23-year-old graduate from India. I am passionate about computers. The best part about me is that I never give up something till I give a try to it. I like coding in C and asm. I like Reverse Engineering. In free time I usually pick up something and try to understand that. Vista is new and have many new security features, so we thought of creating something for Vista.

Vipin Kumar: I am a 22-year-old graduate from India. I like analysing OSes (mainly the internals , kernel stuff etc) and testing OS and network security. Our coding stuff includes development of bootkit, vbootkit and numerous shell-codes and lots of Windows stuff.

For money, we also go for vulnerability assessments, security audits, etc. Life is not easy for us, so we struggle/work a lot to have some hardware like many other guys out there. Feel free to contact us if you need us.

What is Vbootkit?

Nitin & Vipin: Vbootkit is much like a door or a shortcut to access vista's kernel.

A bootkit is a rootkit that is able to load from a boot-sectors (master boot record, CD , PXE , floppies etc) and persist in memory all the way through the transition to protected mode and the startup of the OS. It's a very interesting type of rootkit. All rootkits install when the OS is running because they use the OS' features to load (and also they use the Administrator privileges to install), but bootkits are different, they use the boot media to attack the OS , and thus survive. Vbootkit is a bootkit specific for Windows Vista.

It's a total in-Ram concept. So, it doesn't touch the hard-disk under any condition and thus leaves no proofs. Just give a reboot to a vbootkit running system, and it vanishes just as it was never here.

What 'features' does it provide to Windows users?

Nitin & Vipin: At the moment, it doesn't really provide features to the users. It's just a Proof-of-Concept, that such an attack vector exists which can be used to circumvent the full security of the OS, without being easily traceable.

At the moment it can do a few things which are:

It periodically raises cmd.exe's privilege to SYSTEM after every few seconds.

Modify Registry so as to start the telnet server automatically

Create a user mode thread and deliver the user mode payloads in context of a system(protected) process (LSASS.EXE, Winlogon.exe etc)

Basically, it can do ANYTHING what the user programs it to do, since vbootkit becomes part of the kernel, it can do anything that Vista's kernel can do.

Does it work on all the versions of Windows Vista?

Nitin & Vipin: Yes, It should work with almost all Vista releases, even localised ones, but it will need a little bit of fine tuning. Most probably, it will support Vista Pack 1, but hey this is only a guess.

Have you released your code online?

Nitin & Vipin: No, we haven't released the code for vbootkit, but we have provided binaries to a few antivirus vendors.

However, you can download previous versions of bootkit (which runs on Windows 2000/XP/2003) from the our site. Even source code is provided.

As far as demos are concerned, readers might be interested in the white paper [PDF], slides from our presentation [PPT], videos showing vbootkit in action [AVI1

Nitin & Vipin: Nowadays, many anti-virus solutions don't scan for boot stuff. We got no official response. Whether they are gonna implement it once again or not! But they are interested in our binaries...